Some games like Simpsons Tapped out constantly communicate with its server which take up RAM, battery and also my internet data. So there is absolutely no way to get around it?
Any possibility after jailbreak is available?
Have you gone into Settings -> Notifications and edited notifications there? You should be able to turn of notifications for each app you don't want notifying you anymore.
Push notifications are a different animal, and aren't exactly "multitasking" in the true sense. What's happening is, the phone is listening for push notifications from Apple's servers, for all apps that have them enabled. So, even if the app has been force-quit, and it's no longer running at all, you can still get a notification. Not because the app is running on your phone, but because the app vendor has their notification process still running on
their servers, that gets pushed through Apple.
So basically, push notifications is its own process in iOS (called apsd), and it handles all push notifications for all apps. Even if the app isn't running, it's apsd that receives them and figures out what to do with them.
Does that take up data? Yes, though unless you're getting tons of notifications all of the time, the usage should be pretty negligible, maybe a kilobyte for a really lengthy one.
Does it take up RAM? Only as much as the notification service takes up, which is going to be there whether or not the app has been quit. When you're talking a gigabyte of RAM on the iPhone 5 and iPad 3, it's pretty much a drop in the bucket, and it's still not so bad on an ipHone 4/4S.
Does it take up battery? Again, that depends on how many pushes you get. Disabling push notifications will probably increase your battery life by a small bit if you're receiving a lot of unwanted notifications.
In a nutshell: you're going to find that iOS devices are not really designed for people who are obsessed with what processes are running, and who want to manually manage their RAM. That's all stuff it's going to handle on its own. Some tech geeks (like myself) kinda like that it "just works" and it's reliable enough that I'll just let it do its thing, and find other, more problematic computers to go tinkering with. Others, not so much.
